Do the cardiac muscles utilise the blood passing through them,either oxygenated or deoxygenated?I know that blood it supplied to the cardiac muscles by the coronary arteries,but wont atleast some blood diffuse into the muscle cells?
Can anyone please explain whether it actually happens or not and if not why?

That is a different thing. Things do not diffuse from the inside of the artery or vein directly to it's cells. each artery or vein has it's own capilaries(your vasa vasorum) or if they are really really small they get their nutrients from the intercellular fluid..

"As a biologist, I firmly believe that when you're dead, you're dead. Except for what you live behind in history. That's the only afterlife" - J. Craig Venter

wait. different thing? i do not get it.
you are right if you said it is not directly through into the cells. it will pass capillaries and intertitial-the matrix-first to allow cell get its nutrient.

yes. they transfer the nutrients by diffusion. just the same way that happen in epidermis.. the upper/the more far from membrana basalis the more they reduced in thickness--become thinner--, the more near the cells from membrana basalis the more increasing in thickness-"thicker"-

i think you were get it. but i do not understand the reason why you said different thing.

hei, do not forget that the diffusion/exchange in our blood, in this case, is depend on the thickness of the membrane.

some thing can do diffusion only if the membrane is thin enough (cor is not in this case), the membrane is got enough moisture in order to make it work-just like in the frog skin-, and there is gradien (one side is lack of this, and another is rich with it).

cor is thick-the membrane and the tissue-.
even you can say that cor is have the moisture, but the thickness is not allow the transport.
gradien. even so, it will not allowed by the thick-thing is cor.

vasa vasorum is not cappilaries. cappilaries is not inside either vein and artery. vasa vasorum is like the network inside the artery and vein(thick vein). it allow blood go inside the artery and vein, like a small branch of artery..